Safety lock for elevators



w. E. DAY

SAFETY LOCK FOR ELEVATORS Filed Aug. 21, 1922 2 Sheets-Sheet 1 a Q a QINVENT WALLACE E. DAK

A77OENEYS.

Dec, 9, W. E. DAY

SAFETY LOCK FOR ELEVATORS Filed Aug. 21, 1922 2 Sheets-Sheet 2lNl/E/VTG/Q WALLACE .5. DAY.

Patented Dec. 9, 1924.

UNITED STATES.

PATET WALLACE E. DAY, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO SPENCERELEVATOR 00., OF SAN FRANCISCO, CALIFORNIA, FIRM COMPOSED OF FRANK M.SPENCER.

SAFETY LOOK FOR ELIE VA'IOTEML Application filed August 21, 1922. SerialNo. 583,173.

To all whom it may concern:

Be it known that I, WALLACE E. DAY, a citizen of the United States,residing at the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in Safety Locksfor Elevators, of which the following is a specification.

This invention relates to elevator construction, and particularlypertains to safety means therefor.

At the present time it is legally required that the doors of elevatorhatchways shall be equipped with locking devices havin such a relationto the control mechanism the elevator as to make it impossible to open ahatchway door except when the elevator has stopped at a floor or tostart the elevator before the door of the hatchway is closed. It is theprincipal object of the present invention, therefore, to provideautomatic means especially adapted for normally locking elevatorhatchway doors, and which will operate with the elevator car control ina manner to insure that the control mechanism will remain inoperativeuntil the hatchway door has been properly closed and locked.

The present invention contemplates the use of a lock mechanism carriedon the frame of the hatchway door, and receiving a latch member carriedby a door, said mechanism incorporating electrical means in circuit withthe control mechanism of the elevator whereby the presence of the latchin locking position within the lock will permit the elevator motorcircuit to be completed.

The invention is illustrated by way of example in the accompanyingdrawings in which:

Fig. 1 is a view showing the wiring diagram with which the presentinvention is concerned.

Fig. 2 is an enlarged view in vertical section and elevation showing thelock mechanism.

Fig. 3 is an enlarged view in horizontal section showing the switch ofthe lock mechanism.

Referring more particuarly to the drawing indicates an electric hoistingmotor by which the elevator is raised and lowered. This motor isinitially controlled by direction switches 12 and 13. A main linestarting relay 14 is also provided and is interposed between thedirection switches and floor and car switches. The floor switches areindicated at 15 andare shown as being controlled by a floor control drum16, which may be of any preferred construction. Floor push buttons areindicated at 17 and will permit the usual circuit to be closed in orderto bring the elevator to a particular floor. All of the relays andswitches so far described are of standard construction. The presentinvention, however, is more particularly concerned. with a lockmechanism 18 by which the various control circuits may be made andbroken incident to the opening and closing of the hatchway door, and thepresence of the elevator at any particular floor.

'The lock mechanism comprises a case 19 within which an electromagnet 20is carried. The core 21 of this magnet has an armature 22. This memberis in the form of a plate, and is carried by the lever arm 23, which armis pivoted upon a pin 24. The pin 24 extends through bosses 25projecting from'the side of the case 19. Extending at right angles tothe lever 23 and adapted to move therewith is a latch finger 26. Thisfinger has an engaging lug at its outer end, which may interlock with asimilar lug carried by a latch arm 27. The arm 27 is supported. upon afloor door by which the hatchway is closed and which latch may movehorizontally to project through an opening 29 in the wall of the lockcase. An outwardly extending arm 30 is provided, and is intended to movewith the arm 23 and the latch finger 26. In fact, as here shown, thesethree members are integral and swing around the shaft 24. Carried by thedownwardly projected member 30 are a pair of contact fingers 31 and 32.These members extend horizontally and have curved forward ends for apurpose which will be hereinafter set forth. It is desirable tovertically adjust the contact members, and for that reason they arepivotally carried upon pins 33, which are supported by b-rack .ets 34.The brackets are mounted upon an arm 30, but are insulated from eachother as well as the member 30. Lugs 35 are formed integral with thecontact arms 31 and are acted upon by expansion springs 36 which aredisposed around adjusting screws 37 we tending through the lugs 35 andinto threaded openings of the brackets 34. A contact plate 38 is adaptedto normally engage the upper faces of the two contact members 31 and tocomplete an electrical circuit from one contact member to the other.This plate is carried by an insulating block 39, .WhiQh block is securedto the elevator door and projects through the opening 29' in the lockcase when the door is closed. Attention is directed to the fact that theinitial'engag'emer t of the plate 38 with the contact finger 31 takesplace slightly after the interlockng e gagement of e membe 2 w h i)?latch finger 27. i

In order to mechanically hold the parts in desired relation to eachother when the elevator car has passed from register with any particularfloor a weighted arm 3 0 is provided. This arm is fixed upon apivotedshaft 41 on the outside of the lock case, and carries a roller 42at its up er end. The roller stands in the path 0 a track member notshown in the drawing, but which member is carried by the elei ato'r car,and will swing the arm e0 in the direction of the arrow -awhen the carcon ers to any particular floor. An o positely extending lever at?) isalso fixefon the shaft 41 so to operate in unison with the arm 40. Thislever i3 normally presses against a pin 44 and is actuated by'a weight45. The pin slides horizontally through an opening in the side of the hrbage and presses against the downwardly projected arm 30 tomechanically hold the "2 6 in engagement with'the latch 27 The wiringarrangement of the present invention isused on all standard electricelevator constructions, but i'n' 'order to more clearly disclose theoperatic thelinyeir tion 'a circuit will be descrr ldr Electric currentis delivered thro' l ghlfi d wires 16 and' l'i. ThesewireSare"'confro-lled iby main switch 48 The circuit the cohtinh( is alolg wires 49 and 50. The 49"0i1- nects at 51 with a wire lead to a ordirection switch 12. cnrrentftlfen passes through the motor lO and alongwires I58 and 69. This circuit then .conti along a wire 52 to the maincontrol switch ii, and when this switch is cl'osed 'will be completedalong conductor through the switch 48 and to the wire 56. Wired? alsoconnects with the wire .54 which is secured to contact finger 31 of thelowermost lock' mechanism. circuit may then be completed through theplate BB eng'a Q- ing this finger, thencethrough finger 32 to a wire 55.This wiring intended place the contact fingers '31 and"82of the variouslocks in a series circuit. last contact finger 32 is provided with aconductor 56 leading to the relay coil 5791f the control switch 15;.Circuit through this coll is completed along "wire 58 t6 th'e r nainswitch 48. The wire 49 also is led to' the first lock magnet 20. Aseries of wires 59 are used to place the various lock magnets 20 in aseries circuit which is completed by conductor .60 leading to a contactof the control switch 14. This circuit then proceeds through the switchalong conductor .61 to one side of the floor coil switches 15. Theopposite side oi these switches are separately connected with conductors62 leading to one side of the various tloor push buttons 17. Theopposite sides of all the push buttons are in series and are connectedwith a l etid wire (33. The wires 62 form common leads for the switchesfor the floor coils',"fand also for the coils themselves, cir ciiitsbeing completed through separate condiic to rs 64 connected with contactnieml'iors for the floor controller l6, and thence passing through theseparate leads (S5 and 66 to the direction switches 12 and 13,respectively. When either of the wires or ()6 has been placed in thecircuit, an electric circuit'iri-ll be completed through the respcnemagnets of one of the direction switches, and will then proceed alongreturn. wi est? feed wire 50. hen the switch 12 has been placed inoperation a circuit ii ill be completed through conductor (to tonne sideof the motor .10, and will then proceed along conductor 69 to the switch12; thereafter passing along conductor 52 to the main switch 14; andthence returning to the opposite lead wire along conductors 5:3 and 58'.WVhen the reversal of direction desired the other direction switch willbe actuated and circuit from condiu-tor through wire 70, thence alongwire 71 to the chnducto r 69. The return circuit will be completedthrough conductor (38 to switch in urance flowing along wire 72 toreturn was 521 The important feature of thc l l sent int ention the factthat the cir- "c i1it't hrough the operating magnet 57 of tn 'cchrrorswitch will be broken when any sets; contact fingers 31. and 32 of thelock is'ont er contactwith its plate 38, thus lig'reiilri ng'ithe seriesswitch through the lock to th e' magnet 57.

In operation of the lock when the car is at anyparticular floor the arm40 will be swung in the direction of the arrow --(1-, thus permittingthe lock member 26 to swing downwardly in the direction of the arrow 6This will move the lug at the end of the member 26 from an obstructingposition in relation to the lug of the latch 27, and will permimhcdoorto be open when desired. At the same time that the member 26 falls awayfrom the latch due to the relief of ressureupon the pin 44, the contactmem- @531 and 32 will also fall away from the plate 38 This will breakthe circuit to the -infagnet 57 of the master switch and will malre 'ijtimpossible to start the car until the door has been closed. When thedoor is closed and the car control circuit is closed to Ill) lli'ienergize magnet 20 the plate 38 will move to engage the fingers 31 and32. This will com plete the circuit through the magnet 57 of switch 14to start motor and to hold the circuit closed until the motor circuit isbroken.

The levers l0 at the other floors will at this time be holding the latchmembers in en aging positions while the lever 40 at the floor at whichthe car is stopped will be in such a position as to permit the member 26to stand in a non-engaging position relative to the latch 27. When thecar is in motion and as it passes a fioor but does not stop theenergized magnets 20 will hold all of the r locks but when a stop ismade at a floor the circuit will be broken incident to the interruptionof the control circuits and the arms 4-0 must hold the locks closed.However, when the magnets 20 are energized the plate 22 of thisparticular lock will be drawn upwardly, and will cause the lock member26 to swing to an obstructing position so that it will be impossible forthe latch 27 to be withdrawn. While in this position the control of thecar may be operated and the car may be called to any particular floor byclosing the circuit through the floor button.

It will thus be seen that by the present arrangement a positive andautomatic safety device is provided whereby the doors of an elevatorha'tchway cannot be unlocked except at a time when an elevator is atthat particular floor, and furthermore that the car cannot be opera tedexcept at a time when all of the elevator doors are closed and locked.

While I have shown the preferred form of my invention as now known tome, it will be understood that various changes may be made in thecombination, construction and arrangement of parts without departingfrom the spirit of the present invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is 1. In combination with an elevator car having anelectric controlling system, said car being adapted to travel along ahatchway, the latter being provided with doors at various floors, meansnormally maintaining said doors closed and latched, said means having anelectrical control, means whereby said electrical control will berendered ineffective when the elevator car stops, and mechanical meansadapted to be operated by the elevator car for unlatching the door atthe floor where said elevator car stops.

2. In combination with an elevator car having an electrical controllingsystem, said car being adapted to travel along a hatchway, the latterbeing provided with doors at various floors, a controlling switch insaid controlling system, latching means at each floor normallymaintaining said doors closed and latched, electromagnets havingcircuits maintained closed when said elevator car is in operation, saidelectromagnets maintaining said latching means effective when said caris in operation, mechanical means operated by the elevator car foropening the circuit of said motor controlling switch and the circuits ofsaid magnets when the elevator car stops at a floor, said mechanicalmeans simultaneously rendering said latching means ineffective.

3. In combination with an elevator car, an electric controlling systemtherefor by which it may be stopped at any of the various floors, theelevator being adapted to travel in a hatchway, the latter having a doorat each of the various floors, latch means at each floor adapted tonormally maintain said doors closed and latched, electric meansassociated with the controlling system adapted when said elevator is inoperation to maintain the latch means in position and the doors latched,means whereby said electric means will be discontinued when the car isstopped, mechanical means associated with the latch means at each flooradapted to maintain the same in latched position when the elevator isstopped, the stopping of the elevator at a floor causing said mechanicalmeans at that floor to unlatch the door to permit it to be opened? andmeans whereby the controlling system for the elevator will be renderedinoperative when said door is open.

-WALLACE E. DAY.

